CVE-2021-3667Network attack vector

Service interruption via unreleased storage pool lock

Published Mar 2, 2022 · Updated Feb 13, 2025

Improper locking in libvirt 4.1.0 through 7.5.0 allows remote authenticated users to block storage pool and volume API access. storagePoolLookupByTargetPath obtains a locked, referenced virStoragePoolObj, then returns on an ACL denial without calling virStoragePoolObjEndAPI to release it. Access to the read-write socket under limited ACL permissions is required, and the retained lock prevents other clients from using the affected pool and volume operations.

CVSS severity6.5
Medium
EPSS probability1.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper locking in libvirt 4.1.0 through 7.5.0 allows remote authenticated users to block storage pool and volume API access. storagePoolLookupByTargetPath obtains a locked, referenced virStoragePoolObj, then returns on an ACL denial without calling virStoragePoolObjEndAPI to release it. Access to the read-write socket under limited ACL permissions is required, and the retained lock prevents other clients from using the affected pool and volume operations.

The record

CVE
CVE-2021-3667
Published
Mar 2, 2022
Updated
Feb 13, 2025
Vendor
libvirt
Product
libvirt
Classifications
CWE-667, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 2, 2022CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Fixedin - libvert v7.6.0-rc1 and above

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

libvirt · libvirtversion=Fixedin - libvert v7.6.0-rc1 and above

Published CVSS scores

3.5NVDAV:N/AC:M/Au:S/C:N/I:N/A:P
6.5NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-667Improper Locking
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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